Pumping body for viscosity pumps with curved pumping grooves



Mar. 13, 1923.

J. E'. NOEGGERATH PUMPING BODY'FOR VISCOSITY PUMPS WITH CURVED PUMPING GROOVES Filed Jly 8, 1920 J2? W12 Zar:

Patented Mar. 13, 1.923.

'L itil l .i

JACOB EMIL NOEGGERATH, OF THE HAGUE, NETHERLANDS.

PUMPING BODY FOR VISCOSX'TY PUMPS, 'WITH- GURVED PUMPING GRJDOVES;

Application filed Julyv 8,

i Viscosity Pumps withy Curved Pumping Grooves` lfor which I filed an application in Germany April'.24t, 1917, and of'whichthe following is aspecification.

My invention refers to the pumping of liquids and more especially to viscosity pumps with curvedl channels. In contradistinctionv to centrifugal pumps, for instance, to screw pumps, to gear wheel pumps, to turbine pumps and` so forth, the action of the viscosity pumps. depends. on making use of theviscosity, the cohesion of the particles of the liquid and their adhesion to the walls to create pressure and to convey the liquid.

Up' till now the Opin-ion prevailedthat -the longerthe viscose contact surface oiviscose threads, the higher; the.. pressure. That meant for a given axial lengtha maximum number of threads, that is the smallest. pitch. Further it Wasbelieved that the quantity of thei liquid, semi-solid. or gaseous matter pumped -depended mainly on the'section and the` speed. have now ascertained that. this is erroneous. In contradistinction to the universal beliefregarding viscosity pumps -the following facts have been established.

VVhenthe pitch is very small, that is, when the axisof the groove, approachesthe direction of rotation, the following holds: y l

l. The lviscose com-ponentof conveying l the substance in the direction of thevrotation .inch which means that there are four threads in series, then the total space available for width of thread plus ridge is 25.. Then the Width of the groove may be for instance .18 and of the ridge .07.

If, however, the angle of the thread is 1920. Serial 'Nm 394,863'.

chosen to; correspond` to a; pitch' of 2 tothe inch, then there are only two grooves in series, and the total widthavailable for groove and ridge is ..5. Then there may either. be in paralleltwo grooves of; the above dimensions or it is possiblel toconstruct a slngle one with a widthl oi' groove of for instance .43, the ridgehavingawidth of. .07.` SoA with decreasing pitch the fluid,- carrymg or propelling section isinCreaSed;

ln thel above mentioned examples the in crease is 2 and morefold., y l

The consequence. of conditions 3 and 4 is.: a. That the amount otliquidA propelled becomes small.

o. That the pressureisreducedalsovhich i n ing manner according to the. pressure,L the quantity, or tothe energy required:y

To obtain the4 greatest possible energy., ythe pumping'. body is to be` prlovidedj withay thread the tangenty ofl the pitch angle ofl which lies. between. 0,08; to. 2.57 while` for obtaining the highest possible. pressure it lies between 0.03 and l, andfor obtainingy thev greatest.possiblequantityit lies between i f 0.125 .and 3; v y

The tangent of the pitch angle isheight of pitch divided by'circumference.

To decide whether, in themeaningof. this invention, av pump isan energy pump or a pressure pump orfa quantityl pump, the; followingdeinition may begiven z KMOPDQa/Qan whereby-v the mzui-imumA pressureis given. in atmospheres, thespeedin., number; of, revolt-14 tions. per. minute, i the maximuml opuantity` in liters. per minute,the dimensions. in millimetersA andthe viscosity o proportion tothe viscosity of water.L y y t The constantllOlis a measuring constant depending on the measure chosen. The constant equals 40 if the above mentioned measures are chosen. i

`It this formula gives a result` between l and onA then the pump is a pressure pump.`

If it lies between 1 and 0,'then it is a quantity pump, if it lies between 1/40 andl l0, then it is an energy pump.

Sometimes viscosity pumps are designed for a higher pressure than the one at which they actually-.work and in that case they pump a correspondingly greater quantity. Such pumps are fit as well for high pressure as for great quantity, and the range of tangents of their pitch angles lies inside of the mentioned limits of the general range. Within the limits given above it is a matter of design what pitch to choose.

Formerly viscosity pumps for obtaining the highest possible pressures have been constructed with pitches of less than 0.015, because in using these small tangents the resulting length of the groove is very gieat for a pumping` body of a given axial length and because the opinion prevailed that for this reason the pressure would be high. But

with these pitch angles less than ,1, of the pressure attainable by the invention is reached.

Apart from the correct choice of the pitch very often output and energy can be consid- Y erably enlarged by applying threads of different pitch or by altering the pitch angle of the Dumping groove. Thus sometimes, while using small angles, the output is enlarged, if on the suction sidey of the pump the tangent is larger than near the pressure i side. f

' tions of the device embodying my invention are illustrated diagrammatically by way of example. Tn the drawings- Fig. 1 is a plan view of a viscosity pump piston with a groove of gradually changing pitch angle7 while Fig. 2 is a similar view 0f a piston having a groove, the pitch angle of which changes suddenly.

Fig. 3 is diagram of a viscosity pump piston of disc shape.

Fig. 1 is self-explanatory. In the modification disclosed in Fig. 2 the thread body is preferably composed of several parts so as to facilitate manufacture.

As has been mentioned in the beginning, the invention does not apply exclusively to viscosity thread pumps but comprises generally speaking all viscosity pumps, in which curved channels of any shape are employed for pumping. Thus the channels need not be arranged on cylindrical faces but also on conical or discoid faces. In the last mentioned case they become approximately spirals.

special case of the application of different pitches with channels arranged upon a disk is that of a viscosity pump such as shown in Fig. 3. The grooves or the ridge run in straight lines and parallel to a radius.`

They form different angles to the radii 7', r1, r2, r3, r4, which they intersect, and thus to the direction of the drive, this being perpendicular to the radii. The grooves may be disposed on the rotary or the stationary part and on the outside or inside surface.

lf in the foregoing description high pressure was mentioned, this expression is only to be regarded as relative, and is not merely relative in tbe every day sense of the word, for the height of the pressure attained by viscosity pumps or the resulting velocity of the pumped liquid depends as -well for instance upon the viscosity and upon therotation speed of the pumping body. While therefore, for instance, with oil several atmospheres are to be considered as a high pressure, a pressure of a few centimetres must be considered as high in the sense of the invention with liquids possessing little viscosity.

l wish it to be understood that 1 do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. ln a viscosity pump in combination, a conveying body and a fluid-propelling groove on said body, the tangent of thepitch angle of said groove lying between v0.03 and 3.

2. In a viscosity pump in combination, la rotary conveying body and a fluid-propel ling groove on said body, the tangent of the pitch angle of said groove lying between .03 and 3.

3. ln a viscosity pump in combination, a rotary conveying body and a fluid-propelling groove on said body, the tangent of the pitch.y angle ofsaid groove lying between 0.08 and 2.5 for energy pumps, between 0.03 and 1 for pressure pumps and between 0.125 and 3 for quantity pumps.

t. ln a viscosity pump in combination, a rotary conveying body and a Huid-propelling groove on said body, the tangent of the pitch angle of said groove varying and lying between 0.03 and 3.

Tn testimony whereof l affix my signature.

JACOB EMIL NOEGGRATH. 

